Abstract
Magnetic field gradients reduce the transverse relaxation time of nuclear spins, which usually degrades the sensitivity of atomic sensors based on nuclear spins. We demonstrate improved magnetic field gradient compensation by applying first-order and second-order magnetic gradients simultaneously in a cubic vapor cell containing 87Rb vapor and 129Xe gas. Compared with applying only first-order magnetic gradient compensation, the transverse relaxation time of 129Xe is up to 4.3 times longer when applying both first-order and second-order compensating magnetic gradients, which indicates that the total magnetic gradient is greatly suppressed by the joint compensation in our experiment. The magnetic gradients induced by the polarized 87Rb spins, the static magnetic field, and the residual magnetic field are also explored. As the main sources of internal magnetic inhomogeneities, these gradients are experimentally validated to have a sizable value. Furthermore, the total internal magnetic gradient in the system could be self-compensated when the directions of these internal gradient components are appropriately set. The experimental results in this paper are important for suppressing the magnetic gradients and optimizing the gradient compensation in nuclear magnetic resonance systems.
Highlights
Nuclear magnetic resonance (NMR) has been widely used in medical imaging,1–3 studies of fundamental symmetries,4 neutron polarization,5 precision measurement,6 etc
We demonstrate improved magnetic field gradient compensation by applying first-order and second-order magnetic gradients simultaneously in a cubic vapor cell containing 87Rb vapor and 129Xe gas
Compared with applying only first-order magnetic gradient compensation, the transverse relaxation time of 129Xe is up to 4.3 times longer when applying both first-order and second-order compensating magnetic gradients, which indicates that the total magnetic gradient is greatly suppressed by the joint compensation in our experiment
Summary
Nuclear magnetic resonance (NMR) has been widely used in medical imaging, studies of fundamental symmetries, neutron polarization, precision measurement, etc. Suppressing the effect of magnetic field inhomogeneities is widely recognized as a challenge for NMR systems as it will cause inaccuracies in measurement, loss of resolution due to the decrease in spin relaxation time, and an isotope shift in dual isotope comagnetometers.. In the presence of magnetic field inhomogeneities, spins will precess faster in the regions of a stronger magnetic field than spins in the regions of a weaker magnetic field, and the magnetic field inhomogeneities will lead to precession phase shift, which will increase with time. Such incoherent precessions will cause the damping of total spin polarization and broadening of the NMR linewidth. It is important to investigate the sources of the internal gradients and compensate the magnetic gradients in a more efficient way
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
